tetano
Editor, Senior Moderator
Clin Infect Dis
. 2024 Jul 23:ciae380.
doi: 10.1093/cid/ciae380. Online ahead of print. Preliminary findings from the Dynamics of the Immune Responses to Repeat Influenza Vaccination Exposures (DRIVE I) Study: a Randomized Controlled Trial
Benjamin J Cowling[SUP] 1 2 [/SUP], Sook-San Wong[SUP] 1 3 [/SUP], Jefferson J S Santos[SUP] 4 [/SUP], Lisa Touyon[SUP] 1 3 [/SUP], Jordan T Ort[SUP] 4 [/SUP], Naiqing Ye[SUP] 4 [/SUP], Natalie K M Kwok[SUP] 1 [/SUP], Faith Ho[SUP] 1 [/SUP], Samuel M S Cheng[SUP] 1 [/SUP], Dennis K M Ip[SUP] 1 [/SUP], Malik Peiris[SUP] 1 [/SUP], Richard J Webby[SUP] 5 [/SUP], Patrick C Wilson[SUP] 6 [/SUP], Sophie A Valkenburg[SUP] 3 7 [/SUP], John S Tsang[SUP] 8 [/SUP], Nancy H L Leung[SUP] 1 2 [/SUP], Scott E Hensley[SUP] 4 [/SUP], Sarah Cobey[SUP] 9 [/SUP]
Affiliations
Background: Studies have reported that repeated annual vaccination may influence influenza vaccination effectiveness in the current season.
Methods: We established a 5-year randomized placebo-controlled trial of repeated influenza vaccination (Flublok, Sanofi Pasteur) in adults 18-45 years of age. In the first two years, participants received vaccination (V) or saline placebo (P) as follows: P-P, P-V, or V-V. Serum samples were collected each year just before vaccination and after 30 and 182 days. A subset of sera collected at 5 timepoints from 95 participants were tested for antibodies against vaccine strains.
Results: From 23 October 2020 through 11 March 2021 we enrolled and randomized 447 adults. Among vaccinated individuals, antibody titers increased between days 0 and 30 against each of the vaccine strains, with smaller increases for repeat vaccinees who on average had higher pre-vaccination titers in year 2. There were statistically significant differences in the proportion of participants achieving >=four-fold rises in antibody titer for the repeat vaccinees for influenza A(H1N1), B/Victoria and B/Yamagata, but not for A(H3N2). Among participants who received vaccination in year 2, there were no statistically significant differences between the P-V and V-V groups in geometric mean titers at day 30 or the proportions of participants with antibody titers ≥40 at day 30 for any of the vaccine strains.
Conclusions: In the first two years, during which influenza did not circulate, repeat vaccinees and first-time vaccinees had similar post-vaccination geometric mean titers to all four vaccine strains, indicative of similar levels of clinical protection.
Keywords: antibody; immunogenicity; influenza; vaccination.
. 2024 Jul 23:ciae380.
doi: 10.1093/cid/ciae380. Online ahead of print. Preliminary findings from the Dynamics of the Immune Responses to Repeat Influenza Vaccination Exposures (DRIVE I) Study: a Randomized Controlled Trial
Benjamin J Cowling[SUP] 1 2 [/SUP], Sook-San Wong[SUP] 1 3 [/SUP], Jefferson J S Santos[SUP] 4 [/SUP], Lisa Touyon[SUP] 1 3 [/SUP], Jordan T Ort[SUP] 4 [/SUP], Naiqing Ye[SUP] 4 [/SUP], Natalie K M Kwok[SUP] 1 [/SUP], Faith Ho[SUP] 1 [/SUP], Samuel M S Cheng[SUP] 1 [/SUP], Dennis K M Ip[SUP] 1 [/SUP], Malik Peiris[SUP] 1 [/SUP], Richard J Webby[SUP] 5 [/SUP], Patrick C Wilson[SUP] 6 [/SUP], Sophie A Valkenburg[SUP] 3 7 [/SUP], John S Tsang[SUP] 8 [/SUP], Nancy H L Leung[SUP] 1 2 [/SUP], Scott E Hensley[SUP] 4 [/SUP], Sarah Cobey[SUP] 9 [/SUP]
Affiliations
- PMID: 39041887
- DOI: 10.1093/cid/ciae380
Background: Studies have reported that repeated annual vaccination may influence influenza vaccination effectiveness in the current season.
Methods: We established a 5-year randomized placebo-controlled trial of repeated influenza vaccination (Flublok, Sanofi Pasteur) in adults 18-45 years of age. In the first two years, participants received vaccination (V) or saline placebo (P) as follows: P-P, P-V, or V-V. Serum samples were collected each year just before vaccination and after 30 and 182 days. A subset of sera collected at 5 timepoints from 95 participants were tested for antibodies against vaccine strains.
Results: From 23 October 2020 through 11 March 2021 we enrolled and randomized 447 adults. Among vaccinated individuals, antibody titers increased between days 0 and 30 against each of the vaccine strains, with smaller increases for repeat vaccinees who on average had higher pre-vaccination titers in year 2. There were statistically significant differences in the proportion of participants achieving >=four-fold rises in antibody titer for the repeat vaccinees for influenza A(H1N1), B/Victoria and B/Yamagata, but not for A(H3N2). Among participants who received vaccination in year 2, there were no statistically significant differences between the P-V and V-V groups in geometric mean titers at day 30 or the proportions of participants with antibody titers ≥40 at day 30 for any of the vaccine strains.
Conclusions: In the first two years, during which influenza did not circulate, repeat vaccinees and first-time vaccinees had similar post-vaccination geometric mean titers to all four vaccine strains, indicative of similar levels of clinical protection.
Keywords: antibody; immunogenicity; influenza; vaccination.